Is there any way to add open/close morphs for vag and anus?
Short answer is yes.
In Daz you can create "new morphs", set up controls and link parameters etc.
As i am a Daz noob, i am not going to give suggestions how.
You must look for tutorials on how to erc freez, link controls and all that stuff.
And then you can/must setup the export morph rules to include them when you export as fbx.
I am not familiar with Belnder or defo tho.
You Should probably add Blender tag to the title as that seams to be your target.
I havent tested anything with the G9 Model, but for G8/8.1 exporting morphs and genitals is a pain in the ass.
The Male Penis. aka using Dictator is fine, it will export the morphs without issues or much work.
But the Golden Place is a pain in the ass to export.
It will Export a static morph state fine with the bones/joints but not morphs.
It seams the Daz or the Dev has gone out of his way to make it not export the morphs.
Im not sure if this is the case for AE on G9 aswell.
However you can make the exporter, make separate objects of the morphs.
So you can easily setup new pose controls in Blender i guess.
I dont know how you do it for Blender, but my workaround is just to use the c4d Bridge without actually using it. "only Daz side is used"
Setting up new pose controls is basicaly just a matter of drag and drop for the most parts for me.
While this is not the best solution for performance. it works fine in a 3d render software for the most part.
Altho you can just bake out the animations when done animating for better performance if animating.
So back to you initial question. can it be done yes. but if no pose controls are already made.
You need to do it yourself, which i guess is a tediouse task in Daz.
Or as said by others, find 3rd party stuff.